When restoring a mesial Class II on a maxillary first premolar, how should the mesial concavity be accommodated?

Correct answer: D. Use a custom-contoured wedge, or burnish the band into the concavity

• A. A standard flat wedge and straight band leave a gap in the depth of the concavity.
• B. Deliberately creating an overhang and trimming it afterwards is poor practice; subgingival excess is very difficult to remove completely.
• C. Omitting the wedge guarantees an overhang and a light contact.
• D. CORRECT. The maxillary first premolar has a pronounced MESIAL CONCAVITY (the canine fossa) running from the contact area onto the root. A flat wedge cannot follow that curve, so it fails to seal the band against the tooth in the depth of the concavity and amalgam escapes gingivally. The solution is to CUSTOMISE the wedge — trimming it with a scalpel to match the contour — and to burnish the band into the concavity so it adapts intimately.

Note: The same concavity is a strip-perforation danger zone during endodontic access and post preparation, and it complicates instrumentation during scaling and root planing.